Composite layers or separators for lead acid batteries

ABSTRACT

Disclosed herein are novel or improved fibrous layers, composites, composite separators, separators, composite mat separators, composite mat separators containing fibers and silica particles, battery separators, lead acid battery separators, and/or flooded lead acid battery separators, and/or batteries, cells, and/or methods of manufacture and/or use of such fibrous layers, composites, composite separators, separators, battery separators, lead acid battery separators, cells, and/or batteries. In addition, disclosed herein are methods, systems, and battery separators for enhancing battery life, reducing internal resistance, reducing metalloid poisoning, reducing acid stratification, and/or improving uniformity in at least enhanced flooded batteries.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. application Ser.No. 15/922,052, filed Mar. 15, 2018, which claims priority to and thebenefit of Indian Application No. 201731009500 filed Mar. 18, 2017.

FIELD

In accordance with at least selected embodiments, the present disclosureor invention is directed to novel or improved mats, fibrous layers,separators, composite separators, composite mat separators, compositemat separators containing fibers and silica particles, batteryseparators, lead acid battery separators, batteries, cells, and/ormethods of manufacture and/or use of such mats, separators, batteryseparators, lead acid battery separators, batteries, and/or cells, aswell as vehicles, systems, or devices containing the same. In accordancewith at least certain embodiments, the present disclosure or inventionis directed to novel or improved enhanced composite separators for leadacid batteries, and/or improved methods of making and/or using suchimproved separators, cells, batteries, systems, vehicles, and/or thelike. In accordance with at least certain embodiments, the presentdisclosure or invention is directed to an improved composite separatorfor lead acid batteries and/or improved methods of using such batterieshaving such improved separators. In accordance with at least selectedembodiments, the present disclosure or invention is directed tocomposite separators, particularly separators for lead acid batteries,flooded batteries, enhanced flooded batteries, dry charge batteries,and/or the like. In addition, disclosed herein are methods, systems andbattery separators for enhancing battery life, decreasing shorting,reducing water loss, increasing wettability, reducing acidstratification, improving acid diffusion, reducing active materialshedding, reducing metal induced oxidation, reducing oxidation, reducingheavy metal and/or metalloid poisoning, reducing antimony poisoning,increasing antimony suppression, and/or improving uniformity in one ormore lead acid batteries. In accordance with at least particularembodiments, the present disclosure or invention is directed to animproved separator for lead acid batteries wherein the separatorincludes fibers, one or more binders, silica particles, fillers,additives, surfactants, coatings and/or the like.

BACKGROUND

Lead acid batteries can include one or more battery separators whichdivide, or “separate,” the positive electrode from the negativeelectrode within a lead acid battery cell. A battery separator may haveat least two primary functions. First, a battery separator should beelectrically insulating and should keep the positive electrodephysically apart from the negative electrode in order to prevent anyelectronic current passing between the two electrodes. Second, a batteryseparator should permit an ionic current between the positive andnegative electrodes with the least possible resistance. A batteryseparator can be made out of many different materials, but these twoopposing functions have been met well by a battery separator being madeof a porous nonconductor.

There are many different pathways by which a lead acid battery can failor lose power or lifespan. If the active material is flaked or otherwisesheds from the positive electrode and comes into contact with thenegative electrode, battery performance is reduced. Such a process canbe designated positive active material (PAM) shedding. Acidstratification is a term for the process in which denser concentratedsulfuric acid is accumulated at the bottom of the battery, leading to acorresponding higher amount of water (dilute acid) at the top of thebattery. The reduced levels of acid at the top inhibit plate activationand can induce sulfation. Increased acid levels at the bottomartificially raise the voltage of the battery, which can interfere withbattery management systems. Overall, acid stratification causes higherresistance which leads to shorter battery life and lower batteryperformance.

Grids of positive electrodes in deep cycle flooded batteries are made oflead antimony alloys to enable deep cycling performance. However, duringdeep cycling, antimony from grid alloy dissolves into the electrolyteand reaches the negative electrode and deposits on it, droppingovervoltage for hydrogen evolution resulting in enhanced waterhydrolysis, water loss and poisoning of the negative electrode. This istermed antimony poisoning. Due to this phenomenon, these types offlooded deep cycle batteries require maintenance through the periodicaddition of water to make up for loss of water.

Glass mats or wet laid nonwovens have been explored to address some ofthe challenges mentioned above. These mats or nonwovens could be made ofsynthetic wood pulp and glass fibers, or synthetic fibers held togetherby synthetic or natural (such as natural rubber latex) polymericbinders. Although such materials may exhibit increased oxidationresistance and/or reduced active material shedding, they do notcompletely solve the problems of antimony poisoning and acidstratification.

There is a need for new battery separators and/or new battery technologyto meet and overcome the challenges arising from current lead acidbattery needs, especially to reduce antimony poisoning, increaseantimony suppression, reduce oxidation, reduce water loss, reduceshorting, and/or reduce acid stratification.

SUMMARY

In accordance with at least selected embodiments, the present disclosureor invention may address the above issues or needs, and/or may providenovel or improved mats, fibrous layers, separators, fibrous separators,composite separators, composite mat separators, composite mat separatorscontaining fibers and silica particles, battery separators, lead acidbattery separators, batteries, cells, and/or methods of manufactureand/or use of such mats, separators, battery separators, lead acidbattery separators, batteries, and/or cells, as well as vehicles,systems, or devices containing the same. In accordance with at leastcertain embodiments, the present disclosure or invention is directed tonovel or improved enhanced composite separators for lead acid batteries,and/or improved methods of making and/or using such improved separators,cells, batteries, systems, vehicles, and/or the like. In accordance withat least certain embodiments, the present disclosure or invention isdirected to an improved composite separator for lead acid batteriesand/or improved methods of using such batteries having such improvedseparators. In accordance with at least selected embodiments, thepresent disclosure or invention is directed to composite separators,particularly separators for lead acid batteries, flooded batteries,enhanced flooded batteries, dry charge batteries, and/or the like. Inaddition, disclosed herein are methods, systems and battery separatorsfor enhancing battery life, decreasing shorting, reducing water loss,increasing wettability, reducing acid stratification, improving aciddiffusion, reducing active material shedding, reducing metal inducedoxidation, reducing oxidation, reducing heavy metal and/or metalloidpoisoning, reducing antimony poisoning, increasing antimony suppression,and/or improving uniformity in one or more lead acid batteries. Inaccordance with at least particular embodiments, the present disclosureor invention is directed to an improved separator for lead acidbatteries wherein the separator includes fibers, one or more binders,silica particles, fillers, additives, surfactants, coatings and/or thelike.

In accordance with at least certain objects, aspects or embodiments, thepresent disclosure or invention may provide an improved compositeseparator which overcomes the aforementioned problems, for instance byproviding improved oxidation resistance, improved wicking, improvedwettability, improved acid retention, improvements in acid displacement,improved puncture strength, improvements in electrical resistance (ER),reduced acid stratification, increased acid diffusion, reduced electrodeshedding (for example, reduced PAM shedding) and/or reduced antimonypoisoning. The battery separators described herein may be key forimproving performance for various lead acid batteries, including, butnot limited to, deep cycling batteries (e.g., where antimony suppressionis a need), batteries operating in a partial state of charge, dry chargebatteries (e.g., where oxidation resistance is a need), stationarybatteries, inverter batteries and/or uninterrupted power supply (UPS)batteries (e.g., where reduced acid stratification and/or improved acidmixing is a need), batteries used in solar power, batteries used in windpower, certain batteries in motion, such as truck batteries or batteriesthat undergo high vibration or automobile batteries (e.g., whereimproved ER is a need), enhanced flooded batteries that operate inpartial state of charge, and so forth. The battery separators describedherein may be in a leaf format, cut piece format, sleeve format, pocketformat, envelope format, and the like.

In accordance with at least selected embodiments, the present disclosureor invention may address the above issues or needs and/or may providenovel or improved lead acid battery separators and/or lead acidbatteries. In accordance with at least selected embodiments, the presentdisclosure or invention is directed to novel or improved separators,battery separators, lead acid battery separators, batteries, cells,and/or methods of manufacture and/or use of such separators, batteryseparators, lead acid battery separators, batteries, and/or cells. Inaccordance with at least certain embodiments, the present disclosure orinvention is directed to novel or improved lead acid battery separatorsfor idle start stop (ISS) applications, in enhanced flooded batteries,in a flooded battery, an enhanced flooded battery, an ISS battery, a drycharge battery, an AGM battery, a VRLA battery, a VRLA-AGM battery, agel battery, a tubular battery, a flat plate battery, or the like,and/or improved methods of making and/or using such improved separators,cells, batteries, systems, and/or the like. In accordance with at leastcertain embodiments, the present disclosure or invention is directed toan improved separator for lead acid batteries, the improved lead acidbatteries, and/or improved methods of using such batteries having suchimproved separators. In addition, disclosed herein are vehicles,methods, systems, batteries, cells, and battery separators for enhancingbattery life, reducing acid stratification, reducing antimony poisoning,reducing active material shedding (such as PAM shedding), reducingoxidation, increasing performance, and/or improving uniformity in atleast lead acid batteries. In accordance with at least particularembodiments, the present disclosure or invention is directed to animproved separator for lead acid batteries wherein the separatorincludes fibrous materials, silica particles and/or a binder.

In accordance with at least certain embodiments, the present disclosureor invention may address the above issues or needs and/or may providenovel or improved mats, separators, composite separators, batteryseparators, lead acid battery separators, flooded lead acid batteryseparators and/or battery technology that addresses, meets and/orovercomes the challenges arising from current lead acid battery needs,especially that reduce antimony poisoning, increase antimonysuppression, reduce oxidation (increase oxidation resistance), reducewater loss, reduce shorting, reduce lead requirements, and/or reduceacid stratification, and/or that increase cycle life, increase thewarranty period, and/or the like.

In accordance with at least certain selected embodiments, the compositeseparator may include fibrous materials. Suitable materials includesynthetic and natural fibers, including glass fibers, polymeric fibers,polyesters (such as polyethylene terephthalate fibers (PET fibers)),polyolefins, polyamides, polyimides, polyacrylonitriles,poly(meth)acrylates, cellulose, nylon, and combinations thereof. In someparticular embodiments, the composite separator may include bunches orbundles of fibers, for example, bunches of glass fibers and/or bunchesof synthetic fibers, such as certain polymeric fibers. In addition, incertain embodiments, the composite separator may include twisted bunchesor bundles of fibers, for example, twisted bunches of glass fibersand/or twisted bunches of synthetic fibers, such as certain polymericfibers or combinations thereof. In such embodiments, it is preferredthat in order to retain the bunch format, such bunches of fibers arebound together with a binder that does not dissolve in water and/oraqueous solutions, etc. In such embodiments, that binder may be appliedin various ways, such as sprayed, when the fibers are drawn through aforming orifice. In such instances, such a binder may cure quicklyand/or instantly due to the high temperature at which fiber exits aforming orifice (for example, in a molten phase) and yet the quickcooling to a solid phase that the fiber undergoes. Binder is sprayed notwhen glass fiber bunch exits the orifice as it will be at very hightemperature. In such embodiments involving twisted bunches of fibers,twisting may occur as a result of a rotating or twisting orifice fromwhich fibers being formed exit. As described just above, such twists maybe held in place with the use of various binder(s). In variousembodiments, any combination of twisted yarn and/or twisted bunches orbundles of fibers, and/or twisted individual fibers, and/or bunches offibers, and/or individual fibers may be used in accordance with theprocesses and battery separators described herein. However, the regionto spray binder is carefully chosen to not decompose binder, but to justcure it quickly, where curing is desired, to hold the fiber bunchtogether. By holding the fibers or fiber bunches together by binder,stiffness of fibers increases enormously. Twisted fibers or bunches offibers imparts orders of magnitude higher strength than individualstrands of fiber, and such strength implies or is related to stiffness.Various combinations may provide enhanced stiffness, durability, and/orenhanced prevention of PAM shedding. By way of example, a combination ofsilica, glass fibers, synthetic untwisted fibers, and synthetic twistedfibers may produce a composite mat for use as a battery separator thathas enhanced stiffness and/or enhanced prevention of PAM shedding. Invarious embodiments contemplated herein, about 2% to about 50% of thefibers used in a composite mat may be twisted. In other embodiments, acomposite mat may include about 30% total fibrous material or 30% byweight of the total, fibers; twisted fibers can make up 0% to all of the30% total fibrous content, while untwisted fibers can make up 0% to allof the 30% total fibrous content. Together with twisted glass fibers,twisted synthetic fibers can be added to form the final composite mat.

Generally, it is preferred that the fibrous materials used in thebattery separators described herein are not oxidizable, or notsubstantially oxidized or degraded under conditions found in the contextof a lead acid battery, especially at the positive plate or cathode. Thefibrous materials in the separator can be non-woven, woven, knitted,braided, felt, film, net, and/or mesh. In certain embodiments, thecomposite separator comprises a fibrous layer comprising a fibrousmaterial that comprises a combination of microglass fiber, polyesterstaple fiber, and chopped strand glass fiber. The basis weight of theseparator, or of the fibrous layer comprising the fibrous material, maybe about 10 g/m² to about 200 g/m², including all ranges in between.

In accordance with at least certain selected embodiments, the compositeseparator or fibrous layer may include silica, for instance silicaparticles or flocculated silica particles or flakes. The particles maybe of various sizes, shapes, and formats, and may be dispersedthroughout the composite separator or may be coated, overlaid,impregnated or otherwise disposed on one or both surfaces of thecomposite separator. The silica may provide wettability, small poresize, and/or wicking properties to various layers of the batteryseparators described herein.

In accordance with at least certain selected embodiments, the compositeseparator or fibrous layer may include a binder, for instance apolymeric binder or binders. The binder may be dispersed throughout thecomposite separator or may be coated, overlaid, impregnated, orotherwise disposed on one or both surfaces of the composite separator orfibrous layer.

In accordance with at least certain selected embodiments, a batteryincluding a microporous separator, which battery exhibits reducedelectrode shedding (for example, PAM shedding), is provided. Since theseparator or fibrous layer may be in direct contact with the electrode,it immobilizes any electrode material from dispersing into the battery.The electrode material may also embed itself onto the surface of theseparator or fibrous layer during formation process resulting inimmobilizing PAM and preventing shedding.

In accordance with at least certain selected embodiments, a microporousseparator with decreased antimony and other metal poisoning is provided.Because the separator or fibrous layer has a large area of highly polarsurfaces, for example, high surface area particles, such as silicaparticles, in the separator, metals and metalloids are captured oroccluded or sequestered within the separator.

The separator or fibrous layer may contain one or more performanceenhancing additives, such as a surfactant, along with other inorganicand/or organic additives or agents, residual oil, deflocculants,dispersants, coagulants, and/or fillers. Dispersing agents may include,by way of example, polyethylene glycol (PEG). Such performance enhancingadditives can further reduce separator oxidation, reduce water loss,and/or facilitate the transport of ions across the separator.

In certain selected embodiments, the composite separator is providedwith additional layers or materials. The layers or materials maycomprise latex, polyolefin, phenol-formaldehyde (PF) based resins,crosslinked latex, crosslinked polyolefin, thermoset resin, thermosetbinder, epoxy resin, thermoset polymeric film or combinations thereof.

In certain selected embodiments, the separator is provided with ribs onone or both sides. The ribs may be formed directly in the compositematerial or may be added to a material making up a separate layer, forinstance, an added layer of thermoplastic polymer such as polyethyleneor an added layer of thermoset polymer such as resol or PF resin orpolyester. The ribs may be made on a polymeric film, which film is lateron bonded to the fiber/particle web to form a two layer compositeseparator. In certain embodiments, the present disclosure includes acomposite battery separator that includes a laminate comprising amembrane separator layer, such as a polymer separator layer, such as amicroporous polyethylene membrane separator layer, and a mat or fibrouslayer in accordance with any of the various embodiments set forthherein.

BRIEF DESCRIPTIONS OF THE FIGURES

FIG. 1A schematically depicts a method of making a composite separatoror a layer of a composite separator involving a slurry, and press roll.

FIG. 1B schematically depicts a method of making a composite separatoror a layer of a composite separator involving a fiber stock solution,web formation, a press roll, and a slurry

FIG. 2A depicts a woven fabric used in various methods of making acomposite separator or a layer of a composite separator.

FIG. 2B depicts a method of making a coated final product of theinvention.

FIG. 3A depicts a nonwoven glass mat or fabric used in various methodsof making a composite separator or a layer of a composite separator;

FIG. 3B depicts various methods of making a composite separator or alayer of a composite separator according to the disclosure herein.

FIG. 4 depicts an embodiment of the present invention in which anonwoven separator layer 10 is juxtaposed adjacent to a ribbed separatorlayer 12, for example, a ribbed microporous polymeric membrane separatorlayer 12.

FIG. 5 depicts a composite mat and/or a nonwoven separator layeraccording to various embodiments of the present invention in whichfibers and/or fibrous material 14 is shown.

FIGS. 6A, 6B, and 6C depict another embodiment of a composite mat or aseparator layer formed in accordance with the present disclosure. FIG.6A depicts a surface view of a grid or mesh 16 with open areas oropenings 18. FIG. 6B depicts a cross-section of the same grid or mesh ofFIG. 6A after it has been impregnated with a mixture of binder andfiller, for example, silica filler. In FIG. 6B, the mixture of binderand filler (for example, silica filler) fills the openings 18. Themixture also creates a layer 20, such as a silica layer 20, on each sideof the grid or mesh 16. In certain embodiments, the binder and fillermixture is squeezed through the grid or mesh 16 to create layer 20 oneach side of the grid or mesh 16. In FIG. 6C, an alternative embodiment,the mixture of binder and filler (for example, silica) simply seals theopenings 18 and creates a layer of binder and silica (or a silica layer)20 on only one side of the grid or mesh 16, leaving the grid or mesh 16visible from one side. In another alternative embodiment (not shown),the mixture of binder and filler (for example, silica filler) simplyimpregnates the grid or mesh 16 simply sealing the openings 18 and notcreating any layer of binder and silica on either side of the grid ormesh 16, leaving both sides of the grid or mesh 16 visible.

DETAILED DESCRIPTION

In accordance with at least certain embodiments, the disclosed orinventive layer, material, or separator is preferably a porous compositeseparator (such as a microporous composite separator) containing naturalor synthetic fibers, such as glass fibers, ceramic fibers (alumina,silica, zirconia, aluminum silicate, or the like), cellulosic fibers,polyolefin, polyester, polyvinyl, polyamide, viscose, acrylic,non-conductive carbon fibers or combinations thereof, more preferablyglass fibers (such as microglass fibers, fine fibers of low diameter,possibly used in various combinations of grades/diameters, and/orchopped strand fibers, possibly of slightly higher diameter to giveenhanced stiffness and mechanical strength). Fine glass fibers mayprovide resiliency and/or structural integrity to the battery separatorsdescribed herein. Synthetic and/or polymeric fibers may provideflexibility and/or self-welding capability to fibrous layers of thebattery separators described herein. When PAM shedding is the majorfailure mechanism in batteries such as in high vibration conditions, acomposite mat or fibrous layer containing stiff fibers such as bondedtwisted glass fibers or twisted synthetic fibers can be added to formthe composite or separator. The composite separator further containssilica particles and may optionally contain a polymeric binder. In someselected embodiments the composite separator may be prepared bycombining fibers, silica particles (which may be flocculated) and apolymeric binder, forming a mat by a process, such as a nonwovenprocess, or a woven process, or a wet-laid process or a dry-laid process(after ingredients are dry blended), and then curing the composite atelevated temperature (by way of example only, using heat, using IR,etc.) to bond the fibers and particles together. In other selectedembodiments, a pre-made fiber mat is overlaid, coated, impregnated orotherwise contacted with a mixture of silica particles and polymericbinder. In these embodiments, the fiber mat can be non-woven or woven,braided, knitted, felt, film or mesh.

In certain selected embodiments, the fibers can be glass, cellulose,polyethylene, polypropylene, polyethylene terephthalate (PET), polyvinylchloride, and mixtures thereof. Exemplary mixtures include, but are notlimited to, mixtures of glass fibers with one or more synthetic fibers,for instance, glass and polyethylene, or glass and PET. The weight ratioof the glass:synthetic fiber can be from 100:1 to 1:100, 50:1, to 1:50,25:1 to 1:25, 10:1 to 1:10, 5:1 to 1:5, 10:1 to 1:1, 5:1 to 1:1.

In certain selected embodiments, the fibers can be less than about 20,or 15, or even 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or 0.5 μm in diameter. Theglass fibers can be at least 0.25, 0.50, 0.75, 1.0, 1.25, 1.50, 1.75,2.0, 2.25, 2.5, 2.75 or 3.0 cm in length. In certain embodiments, thepolymeric fibers can be longer than the glass fibers. For example,polymeric fibers may range in length from about 0.25 mm to about 6 cm inlength, in certain embodiments, from about 3 mm to about 25 mm incertain embodiments. Such fibers may be un-crimped; in otherembodiments, such fibers may be crimped. Such fibers may be short-cut orlong-cut. The denier of such fibers, for example, polymeric fibers, maybe about 0.4 denier to about 3.0 denier. In certain embodiments, by wayof example only, PET fibers having a denier of about 0.5 are used tomake a nonwoven separator layer according to the present disclosure. Inother embodiments, all sorts of fibers at various fiber lengths anddenier may be successfully used to create the separators and/or theseparator layers described herein, and such fibers may include, but arenot limited to, those depicted just below in tabular form:

TABLE 1 Generic Type Polyester: Density 1.38 g/cm³ Diameter DenierMicrons (μm) Decitex 0.5  7.16  0.55 3.0 17.53 3.3 6.0 24.79 6.6 12.0 35.06 13.2  25.0  50.60 27.5 

TABLE 2 Diameter (μm) v. Count (dtex) PET PVDE PA6 PA11 PPS ETFE FEPMaterial PP PA66 PA12 PVC PEEK E-CTFE PTFE Density (g/cm³) 0.91 1.141.03 1.38 1.32 1.75 2.1 Diameter (μm) (dtex) (dtex) (dtex) (dtex) (dtex)(dtex) (dtex) 10 0.72 0.90 0.81 1.08 1.04 1.38 1.65 20 2.86 3.58 3.244.34 4.15 5.50 6.60 30 6.40 8.10 7.30 9.80 9.30 12.40 14.90 32 7.30 9.208.30 11.10 10.60 14.10 16.90 34 8.30 10.40 9.40 12.50 12.00 15.90 19.1036 9.30 11.60 10.50 14.10 13.40 17.80 21.40 38 10.30 12.90 11.70 15.7015.00 19.90 23.80 40 11.00 14.00 13.00 17.00 17.00 22.00 26.00 42 13.0016.00 14.00 19.00 18.00 24.00 29.00 44 14.00 17.00 16.00 21.00 20.0027.00 32.00 46 15.00 19.00 17.00 23.00 22.00 29.00 35.00 48 16.00 21.0019.00 25.00 24.00 32.00 38.00 50 18.00 22.00 20.00 27.00 26.00 34.0041.00 52 19.00 24.00 22.00 29.00 28.00 37.00 45.00 54 21.00 26.00 24.0032.00 30.00 40.00 48.00

The separator can contain silica particles of either precipitatedsilica, fumed silica, or silica gel powders of 10 m²/g to 1500 m²/ghaving a high structural morphology. High structural morphology refersto increased surface area of meso-, micro- and macro-porous or networkedor fluffy structured silica. In certain embodiments, the particles canhave a high surface area, for instance, greater than 100 m²/g, 110 m²/g,120 m²/g, 130 m²/g, 140 m²/g, 150 m²/g, 160 m²/g, 170 m²/g, 180 m²/g,190 m²/g, 200 m²/g, 210 m²/g, 220 m²/g, 230 m²/g, 240 m²/g, or 250 m²/gor even much higher as noted above. A silica with high structuralmorphology may have a high oil absorption rate, for instance, greaterthan about 150 ml/100 mg, 175 ml/100 mg, 200 ml/100 mg, 225 ml/100 mg,250 ml/100 mg, 275 ml/100 mg, 300 ml/100 mg, 325 ml/100 mg, or 350ml/100 mg. However, silica having a lower or low oil absorption rate mayalso be employed in making the battery separators described herein.

In some selected embodiments, the silica has an average particle sizeless than 50 μm, 20 μm, 10 μm, 5 μm, 4.5 μm, 4.0 μm, 3.5 μm, 3.0 μm, 2.5μm, 2.0 μm, 1.5 μm, 1.0 μm, or 0.5 μm. In some selected embodiments, thesilica has an average particle size of at least 0.5 μm, 1.0 μm, 1.5 μm,2.0 μm, 2.5 μm, 3.0 μm, 3.5 μm, 4.0 μm, 4.5 μm or 5 μm. In certainselected embodiments, the silica particle size is selected so that theparticles do not congregate within the intra-fiber or inter-fiberspaces. In such embodiments, acid wicking is enhanced by the presence ofthe open spaces. While not wishing to be bound by theory, in variousembodiments, the silica particle is flocculated in a binder so that itessentially increases in size. Binder can precipitate around silica orsilica can precipitate with other silica particles and may become coatedwith binder or binder alone could precipitate and form particulates.Such a flocculate might get caught in the open spaces formed by variousnetworks of fibers and settle thereby forming a composite mat. Duringsettling on the formation wire, for example, in a wet-laid process ofmaking a nonwoven composite fiber mat, fibers, fillers, binders aresettling together, and fillers are being caught in between the networkof all of these materials and settling there, all of which ultimately isforming a web on the formation wire

In certain selected embodiments, the silica or other porous ceramicdielectric materials can be flocculated with binders prior to combiningwith the fibers. In certain embodiments, flocculants may be multivalentcations such as Al, Ca, or Mg. These positively charged moleculesinteract with negatively charged particles and molecules to reduce thebarrier to aggregation. The ions are chosen in such a way that they donot interfere with the lead acid battery electrochemistry. Many of thesechemicals under appropriate pH and salinity react with water to forminsoluble hydroxides which, upon precipitating, link together to formlong chains, physically trapping small particles to the larger floc.Flocculating agents are aluminum, aluminum chlorohydrate, aluminumsulfate, calcium oxide, calcium hydroxide, polyacrylamide, sodiumaluminate, sodium silicate and natural flocculants (such as chitosan,gelatin and guar gum). Suitable flocculating agents include acids suchas sulfuric acid or Superfloc® flocculants and/or coagulants. Neutral orionic surfactants can also be used to flocculate silica particles.Polyethylene oxide can also be used as flocculant. The flocculant's maineffect is to disturb the stability of the colloidal solution formed bysilica in binder and cause precipitation. In some embodiments, a binderis included in making the composite separator. The binder bonds togetherthe fibers, the silica, other particles, etc. as part of the compositemat or separator. The binder should not fill all free spaces and/orpores in the composite or system, and the binder content in the systemis adjusted to ensure the same (e.g., in some embodiments having about10% or less binder in the materials used to make the compositeseparator). In some embodiments, the binder is an aqueous binder and/oris soluble or miscible in water. In some embodiments, the binder is alatex or rubber particle. The binder can be an acrylic binder, by way ofexample, styrene acrylate, or poly methyl (meth) acrylate dispersion oremulsion. In other embodiments, the binder may include GMA (glycidylmethylene acrylate) which when treated with radiation will cross-linkand/or cure and hold the fibers and particles together. The bindersuseful herein include the self-crosslinking or self-curing types as wellas those binders that are cross-linkable or curable by radiation (suchas e-beam radiation, ultraviolet (UV) energy, infrared (IR) radiation,and so forth). The binder can be a water-based acrylic. In addition, inother embodiments, the binder may be water-based epoxy. In otherembodiments, the binder may be a polyurethane emulsion or phenolformaldehyde or cresol resin. Various binders, such as those describedabove, are electrochemically neutral in the battery system and mayprovide improved puncture resistance to the battery separators describedherein. In particular, when a binder is used that is cured and/orcross-linked, the resulting separator or separator layer may havesignificantly improved puncture resistance. When thermosetting polymericbinders such as epoxy or phenol formaldehyde or resol resins are used,the stiffness of the composite mat becomes very high, similar, by way ofexample only, to certain commercial separators available from Daramic,LLC of Charlotte, N.C., such as Daramic® DARAK separator product lines.When stiffness is high, the mats provide excellent PAM support and/orPAM retention and/or reduced PAM shedding. In certain very specificembodiments, where a significantly higher puncture resistance isobtained for the composite separator or the composite separator layerherein, the separator is preferably used in leaf format or cut pieceformat rather than, for example, a wrap, sleeve, or envelope format. Dueto the polar nature of the binder, the electrical resistance (ER) ofseparator is also low.

In some embodiments, the binder can be any polymer in suspension inwater (for example, for a wet-laid nonwoven process). The suspension canbe disturbed by changing the pH of the solution or the suspension. ThepH change may result in coagulation (and/or flocculation) of particlesthat may be a combination of both binder and silica. The particle sizeof silica increases to an extent that it settles between variousnetworks of fibers. In certain embodiments, the binder(s) used to makethe composite separator has equal affinity to the fibers, the silica,the particles, any fillers, and the like used to make the compositeseparator. In other embodiments, a binder is selected to have a strongeraffinity for one or more of these components (versus the othercomponent(s)) in the composite separator. In these embodiments, thecomposite mat or separator may be formed with certain channels toenhance wicking and/or enhance acid diffusion.

In certain embodiments, the silica is flocculated in the polymericbinder and then combined with fibers. In certain embodiments, the silicais flocculated in a suspension with approximately neutral pH, while inother embodiments, the silica is flocculated in an acidic medium, suchas sulfuric acid. A zeolite can be added to the mixture as one of thefiller materials, thereby providing zeolites entangled within thecomposite mat. The zeolite reduces metal and metalloid movement throughthe composite, thereby reducing metal induced oxidation, antimonypoisoning and the like. The mixture may also include minor amounts ofother additives or agents as is common in the separator arts (such aswetting agents, colorants, antistatic additives, and/or the like).

Other various filler(s) may be used in various embodiments of thepresent disclosure. By way of example only, a filler that may be used inplace of some silica within the separator or the composite separator mayinclude titania, lignin sulfonate, barium sulfate, milled glass powder,PVC particles, phenolic resin particles, cellulosic particles, aluminaparticles, natural, synthetic, organic, and/or inorganic particles,fibers, and/or pieces, and/or the like, and combinations thereof.

The flocculated silica mixture may be combined with fibers, optionallyblended for a period of 10, 20, 30, 45, 60, 75, 90 or 120 seconds, andthen wet laid or air laid on a conveyor belt to obtain the compositemat. The mat may be washed with water, dilute acid (e.g., pH of about 1,2, 3, 4 or 5) or other binder solution to bind the silica and the fibersand/or to remove the binder. Suction may be applied through the conveyorbelt to further remove binder and/or compress the fiber/silica blend. Insome embodiments, substantially most of the binder is removed, while inother embodiments the binder remains in the composite mat to a differentdegree. For example, in some embodiments, there is no washing with wateror acid as such might remove too much of the binder or remove the binderto an undesirable extent. Furthermore, in certain embodiments, theflocculated silica mixture already contains binder, and the compositemat can be cured as-is. The conveyor belt may be substantially flat, ormay have areas of negative or positive relief to impart ribs or otherembossments into the composite mat.

The flocculated mixture can be added as second step also. In suchembodiments, formed first is the interpenetrating network of fibers.Then the flocculated mixture of silica may be added. In such instances,the silica particles may not distribute uniformly through thicknessdirection, which may be desirable for various embodiments. By way ofexample only, if a mixture of flocculated silica is allowed to settlefor a longer period of time, one side of the resulting mat may have lesssilica and more fibers, and in certain cases, one side of the resultingmat may appear to have no silica and only fibers. Such a feature may bedesirable in certain instances, as the surface next to positive platemay desirably have more fiber or fiber alone to reduce or eliminate acidstratification.

In certain selected embodiments, the fibers are formed into a mat, andthe flocculated silica/binder mixture is added thereto. The fibrous matmay be dipped in the flocculated silica/binder mixture, or the mixturemay be coated onto the surface of the mat.

In some selected embodiments, the separator or fibrous layer may be madeby

-   -   a) preparing a mixture comprising fibers, polymeric binder and        flocculated silica, and    -   b) forming a non-woven composite from the mixture.

A plurality of zeolite particles may be added to the mixture to give acomposite mat containing zeolites. In some embodiments, this may alsoinclude, in addition to such zeolites, or in place of such zeolites,aluminates, silicates, alumina, etc. The non-woven composite may beformed with the application of suction to remove some or all of thebinder.

In some selected embodiments, the separator may be made by

-   -   a) providing a glass fibrous mat;    -   b) forming an impregnation mixture comprising flocculated silica        and polymeric binder;

and

-   -   c) impregnating the glass fibers with the impregnation mixture.

The impregnation step can be performed by blending with fiber or as anafter process such as spraying, curtain coating, dip and squeeze,foulard (i.e., foaming without pressure) or foaming under pressure.Spraying a binder, for example, an acrylic binder, may provide the webwith improved strength and/or integrity. The glass fibrous mat and/orthe impregnation mixture may contain one of more of zeolites or otheradditives as described above.

In certain selected embodiments, the composite mat is further cured.

After the composite mat is formed, it can be further compressed usingeither a machine press or calender stack. According to certain selectedembodiments, the composite separator has a thickness that is less thanabout 2.0 mm, 1.0 mm, 0.9 mm, 0.8 mm, 0.7 mm, 0.6 mm, 0.5 mm, 0.4 mm,0.3 mm, 0.2 mm, or 0.1 mm. In some selected embodiments, the compositeseparator has a thickness from about 0.1-1.0 mm, 0.1-0.5 mm, 0.1-0.4 mm,or 0.1-0.3 mm. As a result of the calendering process, the composite matcan have different surface features (e.g., ribs, serrations, embossedfeatures, etc.). For example, a calender roll may be ribbed to providethe separator layer or layers with increased overall thickness.Additionally, the calender roll may have a specific profile designthereon to provide a given profile to the separator. The calender rollmay be a corrugated and/or embossing roll to provide a flat sheet layerof the separator and/or an already-ribbed portion of the separator witha higher overall thickness.

The separators disclosed herein can have a final porosity greater than50%, 55%, 60%, 65%, 70%, 75%, 80% or 85%. Porosity may be measured usinggas or liquid porometer and mercury porosimeter. The composite separatorcan have a median or average pore size no greater than 10 μm, 9 μm, 8μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm or 1 μm. The composite can havean average pore size of at least 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7μm, 8 μm, 9 μm, or 10 μm. The minimum pore size of the compositeseparator can be no less than 0.5 μm, 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm,3.0 μm, 3.5 μm, 4.0 μm or 5.0 μm. The maximum pore size of the compositeseparator can be no greater than 50 μm, 40 μm, 30 μm, 25 μm, 20 μm, 17.5μm, 15 μm, 12.5 μm, or 10 μm.

In certain embodiments, the separator can have ribs on at least oneface. The ribs can facilitate processing during the formation of thecomposite and/or folding steps, decrease acid stratification, and/orpromote mixing and increase acid diffusion at the boundary layer betweenthe electrode and bulk electrolyte. In accordance with at least anotherobject of the present invention, there is provided a porous compositeseparator with cross-ribs. Cross ribs refer to ribs which extend in adirection other than the vertical edges of the separator. In someembodiments of the present invention, the cross ribs can have a ribheight of at least 0.005 mm, 0.01 mm, 0.025 mm, 0.05 mm, 0.075 mm, 0.1mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or1.0 mm or 2 mm. The total thickness of the separator can be adjusted bychanging the rib height for the given backweb (or back web) thickness.The separator can have a cross-rib height between 0.005-1.0 mm, 0.01-0.5mm, 0.025-0.5 mm, 0.05-0.5 mm, 0.075-0.5 mm, 0.1-0.5 mm, 0.2-0.4 mm,0.3-0.5 mm, 0.4-0.5 mm. Other ribs or embossments can be formed byembossing or over-embossing rolls or rollers. The ribs may be made ofany polymeric materials and can be dispensed or formed on the surface ofthe film, sheet or fiber mat and cured, or may be formed during theprocess of forming the film, sheet or fiber mat through the calenderingprocess (or may be embossed ribs formed after calendering).

The separator or fibrous layer or layer surface(s) may contain one ormore performance enhancing additives, for instance hydrophilic coating.The hydrophilic coating can include a surfactant. Suitable surfactantsinclude surfactants such as salts of alkyl sulfates; alkylarylsulfonatesalts; alkylphenol-alkylene oxide addition products; soaps;alkyl-naphthalene-sulfonate salts; dialkyl esters of sulfo-succinatesalts; quaternary amines; block copolymers of ethylene oxide andpropylene oxide; and salts of mono and dialkyl phosphate esters. Theadditive can be an anionic surfactant. In addition, in certainembodiments, the additive can be a non-ionic surfactant such as polyolfatty acid esters, polyethoxylated esters, polyethoxylated alcohols,polyethylene oxide (PEO), alkyl polysaccharides such as alkylpolyglycosides, acid-soluble sugars, and blends thereof, amineethoxylates, sorbitan fatty acid ester ethoxylates, organosilicone basedsurfactants, ethylene vinyl acetate terpolymers, ethoxylated alkyl arylphosphate esters, sucrose esters of fatty acids, organic acids such assuccinic acid and hydroxy acids. In embodiments of the presentdisclosure in which a composite separator is made as a nonwoven mat,these types of additives may be added to create benefits such asreducing antimony poisoning. In embodiments of the present disclosure inwhich a composite separator is made as a nonwoven mat laminated to orjuxtaposed with a polyethylene-based separator membrane, these types ofadditives may create benefits such as surfactants would (increasedwetting with electrolyte). The additive or surfactant used in variousembodiments of the present invention may be a surfactant having arelatively low HLB value. For example, in certain embodiments herein,the surfactant used has an HLB value of lower than about 6, in someembodiments, lower than about 5, in some embodiments, lower than about4, and in other embodiments, lower than about 3, in still otherembodiments, lower than about 2, and in yet other embodiments, lowerthan or equal to about 1. As is known in the art, an “HLB” value refersto the hydrophile lipophile balance of the given material. In someembodiments, the additive or surfactant, is insoluble or only difficultysoluble in each of water and sulphuric acid. In still other embodimentsof the present invention, the surfactant is one that is more hydrophobicin its characteristics than hydrophilic. In other embodiments, thesurfactant used herein may be one that is an oil-soluble ororganic-soluble surfactant. In other various particular embodiments, thesurfactant is one that is not soluble in water, aqueous solution, orsulphuric acid and has an HLB value of from about 1 to about 3. In otherembodiments, the surfactant used herein is one that is not soluble oronly difficulty soluble in water, aqueous solution, or sulphuric acidand has an HLB value of less than about 6, preferably less than about 5.In other various embodiments of the present invention, the surfactant orsurfactants added to (or coated onto) the battery separator or fibrouslayer is one or more surfactants having an HLB value of about 3 or less.

The battery separators or fibrous layers can be provided in various wayswith the additive, agents, fillers, or additives. The additives can forexample be applied to the separator when it is finished and/or added tothe mixture used to produce the separator.

The additive can be present at a density of at least about 0.5 g/m², 1.0g/m², 1.5 g/m², 2.0 g/m², 2.5 g/m², 3.0 g/m², 3.5 g/m², 4.0 g/m², 4.5g/m², 5.0 g/m², 5.5 g/m², 6.0 g/m², 6.5 g/m², 7.0 g/m², 7.5 g/m², 8.0g/m², 8.5 g/m², 9.0 g/m², 9.5 g/m², or 10.0 g/m². The additive can bepresent on the separator at a density between about 0.5-10 g/m²,1.0-10.0 g/m², 1.5-10.0 g/m², 2.0-10.0 g/m², 2.5-10.0 g/m², 3.0-10.0g/m², 3.5-10.0 g/m², 4.0-10.0 g/m², 4.5-10.0 g/m², 5.0-10.0 g/m²,5.5-10.0 g/m², 6.0-10.0 g/m², 6.5-10.0 g/m², 7.0-10.0 g/m², 7.5-10.0g/m², 5.0-10.5 g/m², 5.0-11.0 g/m², 5.0-12.0 g/m², or 5.0-15.0 g/m².

The application may also take place by dipping the battery separator inthe additive or a solution of the additive and subsequently optionallyremoving the solvent, e.g. by drying.

In certain embodiments, the additive may be represented by a compound ofFormula (I)

R(OR¹)_(n)(COOM_(1/x) ^(x+))_(m)  (I)

in which:

-   -   R is a linear or non-aromatic hydrocarbon radical with 10 to        4200 carbon atoms, preferably 13 to 4200, which may be        interrupted by oxygen atoms;    -   R¹=H, —(CH₂)_(k)COOM_(1/x) ^(x+), or —(CH₂)_(k)—SO₃M_(1/x)        ^(x+), preferably H, where k=1 or 2;    -   M is an alkali metal or alkaline-earth metal ion, H⁺ or NH₄ ⁺,        where not all the variables M simultaneously have the meaning        H⁺;    -   n=0 or 1;    -   m=0 or an integer from 10 to 1400; and    -   x=1 or 2.

The ratio of oxygen atoms to carbon atoms in the compound according toFormula (I) being in the range from 1:1.5 to 1:30 and m and n not beingable to simultaneously be 0. However, preferably only one of thevariables n and m is different from 0.

By non-aromatic hydrocarbon radicals is meant radicals which contain noaromatic groups or which themselves represent one. The hydrocarbonradicals may be interrupted by oxygen atoms (i.e., contain one or moreether groups).

R is preferably a straight-chain or branched aliphatic hydrocarbonradical which may be interrupted by oxygen atoms. Saturated,uncross-linked hydrocarbon radicals are quite particularly preferred.However, as noted above, R may, in certain embodiments, be aromaticring-containing.

Through the use of the compounds of Formula (I) for the production ofbattery separators, they may be effectively protected against oxidativedestruction.

Battery separators are preferred which contain a compound according toFormula (I) in which:

-   -   R is a hydrocarbon radical with 10 to 180, preferably 12 to 75        and quite particularly preferably 14 to 40 carbon atoms, which        may be interrupted by 1 to 60, preferably 1 to 20 and quite        particularly preferably 1 to 8 oxygen atoms, particularly        preferably a hydrocarbon radical of formula        R²—[OC₂H₄)_(p)(OC₃H₆)_(q)]—, in which:        -   R² is an alkyl radical with 10 to 30 carbon atoms,            preferably 12 to 25, particularly preferably 14 to 20 carbon            atoms, wherein R² can be linear or non-linear such as            containing an aromatic ring;        -   P is an integer from 0 to 30, preferably 0 to 10,            particularly preferably 0 to 4; and        -   q is an integer from 0 to 30, preferably 0 to 10,            particularly preferably 0 to 4;        -   compounds being particularly preferred in which the sum of p            and q is 0 to 10, in particular 0 to 4;    -   n=1; and    -   m=0.

Formula R²—[(OC₂H₄)_(p)(OC₃H₆)_(q)]— is to be understood as alsoincluding those compounds in which the sequence of the groups in squarebrackets differs from that shown. For example according to the inventioncompounds are suitable in which the radical in brackets is formed byalternating (OC₂H₄) and (OC₃H₆) groups.

Additives in which R² is a straight-chain or branched alkyl radical with10 to 20, preferably 14 to 18 carbon atoms have proved to beparticularly advantageous. OC₂H₄ preferably stands for OCH₂CH₂, OC₃H₆for OCH(CH₃)₂ and/or OCH₂CH₂CH₃.

As preferred additives there may be mentioned in particular alcohols(p=q=0; m=0) primary alcohols being particularly preferred, fattyalcohol ethoxylates (p=1 to 4, q=0), fatty alcohol propoxylates (p=0;q=1 to 4) and fatty alcohol alkoxylates (p=1 to 2; q=1 to 4) ethoxylatesof primary alcohols being preferred. The fatty alcohol alkoxylates arefor example accessible through reaction of the corresponding alcoholswith ethylene oxide or propylene oxide.

Additives of the type m=0 which are not, or only difficulty, soluble inwater and sulphuric acid have proved to be particularly advantageous.

Also preferred are additives which contain a compound according toFormula (I), in which:

-   -   R is an alkane radical with 20 to 4200, preferably 50 to 750 and        quite particularly preferably 80 to 225 carbon atoms;    -   M is an alkali metal or alkaline-earth metal ion, H⁺ or NH₄ ⁺,        in particular an alkali metal ion such as Li⁺, Na⁺ and K⁺ or H⁺,        where not all the variables M simultaneously have the meaning        H⁺;    -   n=0;    -   m is an integer from 10 to 1400; and    -   x=1 or 2.

As suitable additives there may be mentioned here in particularpolyacrylic acids, polymethacrylic acids and acrylic acid-methacrylicacid copolymers, whose acid groups are at least partly, i.e. preferably40%, particularly preferably 80%, neutralized. The percentage refers tothe number of acid groups. Quite particularly preferred arepoly(meth)acrylic acids which are present entirely in the salt form. Bypoly(meth)acrylic acids are meant polyacrylic acids, polymethacrylicacids and acrylic acid-methacrylic acid copolymers. Poly(meth)acrylicacids are preferred and in particular polyacrylic acids with an averagemolar mass Mw of 1,000 to 100,000 g/mol, particularly preferably 1,000to 15,000 g/mol and quite particularly preferably 1,000 to 4,000 g/mol.The molecular weight of the poly(meth)acrylic acid polymers andcopolymers is ascertained by measuring the viscosity of a 1% aqueoussolution, neutralized with sodium hydroxide solution, of the polymer(Fikentscher's constant).

Also suitable are copolymers of (meth)acrylic acid, in particularcopolymers which, besides (meth)acrylic acid contain ethylene, maleicacid, methyl acrylate, ethyl acrylate, butyl acrylate and/or ethylhexylacrylate as comonomer. Copolymers are preferred which contain at least40 wt.-%, preferably at least 80 wt.-% (meth)acrylic acid monomer, thepercentages being based on the acid form of the monomers or polymers.

To neutralize the polyacrylic acid polymers and copolymers, alkali metaland alkaline-earth metal hydroxides such as potassium hydroxide and inparticular sodium hydroxide are particularly suitable. In some selectedembodiments, the microporous separator can have a greater proportion oflarger pores while maintaining the average pore size no greater thanabout 1 μm, 0.9 μm, 0.8 μm, 0.7 μm, 0.6 μm, or 0.5 μm. In someinstances, the pore size can be increased by stretching or otherwisephysically manipulating the separator post-extrusion.

In certain selected embodiments, the separator or fibrous layer mayfurther contain one or more phosphate induced metal stabilizationmaterials (often referred to as PIMS material or PIMS mineral). By wayof example only, a PIMS mineral derived from fish bone (such ascommercial, lab ground fish meal) has been shown to have greatestaffinity for metal ions. In accordance with at least certainembodiments, it is preferred that the fish bone powder be added tosubstitute for a portion of the silica at substitution levels of about1% to 20% of the silica, more preferably about 2% to 10%, and mostpreferably at about 2% to 5%. In accordance with at least other certainembodiments, it is preferred that the ground fish bone powder (groundfish meal) be added to substitute for a portion of the silica atsubstitution levels of about 1% to 50% or more of the silica, morepreferably about 5% to 30%, and most preferably at about 10% to 20%.

Besides reducing metalloid poisoning and acid stratification, preferredseparators are also designed to bring other benefits. In particular, thecomposite separators according to the present invention, made as astand-alone nonwoven mat and/or a nonwoven mat used with a polymer orpolyethylene membrane, may provide increased protection against dendritegrowth through the separator. In addition, with regard to assembly, theseparators are more easily passed through processing equipment, andtherefore more efficiently manufactured. To prevent shorts during highspeed assembly and later in life, the separators may have superiorpuncture and oxidation resistance when compared to standard PEseparators. The separators described herein (stand-alone nonwovenseparators and/or one or more nonwoven separator mat layer(s) combinedwith one or more polymer or polyethylene film or membrane layer(s)) maybe in various formats, such as a cut piece, an envelope, a sleeve, apocket, or the like. For embodiments where the separator is an envelope,sleeve, pocket, or the like, it may wrap the positive and/or negativeplate in the lead acid battery. In certain specific embodiments, as thepositive and/or negative plate is wrapped with one of the improvedseparators disclosed herein, it may be further enhanced by the additionof supplemental or additional active material inside the wrap (insidethe envelope or pocket or sleeve or the like). Generally, combined withreduced metalloid poisoning and acid stratification, batterymanufacturers are likely to find improved and sustained electricalperformance in their batteries with these new separators.

In addition, various specific methods of preparing the batteryseparators of the present invention may be employed. In one particularembodiment, organic fiber is combined with inorganic fiber and filler ineither a dry-laid process or a wet-laid process. For the dry-laidprocess of this embodiment, depicted generally in FIG. 1A, all of theraw materials are blended (e.g., the inorganic fibers, such asmicroglass fibers, the organic fibers, such as polyester fibers, thefiller(s), such as silica, a thermoplastic resin, such as polybutyleneterephthalate (PBT) resin, and a binder, such as acrylate latex,followed by casting and curing. The curing may comprise one or more ofe-beam radiation, UV energy curing, IR radiation curing, or the like.For the wet-laid process of this embodiment, depicted generally in FIG.1B, a fiber stock solution of the blend of organic and organic fibers isformed into a web, which is then loaded with binder and silica slurry,followed by curing.

In another embodiment, instead of using glass fiber, a woven inner layeris employed for silica loading. In this embodiment, depicted generallyin FIG. 2, a woven fabric (shown generally in FIG. 2A, is loaded withsilica, resin, and additives to create a coated final product after asqueeze roll is used (see FIG. 2B). In such an embodiment, the silicaemployed may be a silica with a lower density than that typicallyemployed in lead acid batteries so that it does not settle in the bathused for silica loading of the woven fabric. In various embodimentssimilar to this embodiment, rather than the dipping apparatus depictedin FIG. 2B, the separator or separator layer can be made using the sametype of woven layer, but with coating, spraying, roller, doctor blade,or the like, used for adding the silica, resin, and additive(s). In suchembodiments, the squeeze roll depicted in FIG. 2B may be used in thisembodiment as well.

In yet another embodiment, a silica coating is added (surface loaded) toone side, or both sides, of a glass retention mat or a woven fabric or anonwoven fabric, using a binder, such as an acrylic latex binder. Thesame is generally depicted in FIG. 3. For various nonwoven mats and/orfabrics in which fibers are already bound by resin, the silica will stayon the top surface of the mat as a coating. For various woven fabricswith more open areas, the binder+silica will go through the bulk andseal those open areas. Silica will then be located on the surface of thefabric or mat as well as inside the fabric or mat. There can be manyvariations for the above two cases or embodiments, by way of exampleonly, (1) silica on the surface of a bonded fiber mat, (2) silicahomogeneously dispersed in the bulk of a woven mat, (3) silica on thesurface in case (1) just above can be squeezed into the bulk giving agradation of silica into the fiber mat, and so forth. For variousnonwoven glass mats, a two-sided coating of the silica slurry is addedwithout impregnation into the bulk of the glass mat. Similarly, forvarious woven fabrics, a two-sided application of the silica slurry isapplied to the woven fabric. In the embodiments reflected herein wheresilica slurry is impregnated into a fabric or mat, such is done bypushing the slurry inside of the substrate (the fabric or mat). Withinthese processes, the pre-press roll may imprint or curl the substrate tocreate surface irregularity which may be helpful in ensuring adhesion ofthe silica coating on the surface of the substrate. Similarly, incertain embodiments, such a press roll may be designed with patterns orundulations to impart irregularity to the surface of the substrate priorto coating. In addition, in each one of these embodiments, the silicaslurry may also contain fibers, such as microglass fibers, to form acomposite coating that includes not only silica and resin binder butalso glass fiber.

EXAMPLES

The following examples further illustrate at least selected separator orfibrous layer embodiments of the instant invention.

Example 1

About 1.0 g of glass fibers (by way of example only, glass fiberscommercially available as Johns Manville Microstrand 100 or 200 seriesfibers) with a diameter in the range from about 0.2 μm to about 0.8 μmare dispersed in a liter of water by using a blender. After blending for30 minutes, this mixture is dropped in a tank with a formation wirefixed at the bottom. The content is diluted further to get 0.01% ofglass fiber in water. In a separate beaker, 10 g of precipitated silicais weighed and to this 4 g of binder (by way of example only, RhoplexHA-16) is added. The entire mixture is diluted with 200 ml of water. Tothis mixture, dilute sulfuric is added in drops until the clear liquidturns cloudy indicating coagulation or flocculation of binder aroundsilica. This mixture is dropped into the tank containing glass fiber andthe whole mixture is stirred to make it homogeneous. The water is thendrained by applying suction from the bottom of the tank. The fibers,particles and binders settle at the bottom on top of the formation wireto form the web. This is placed in an oven at 60° C. to drive theremaining water off. The dried web is transferred to a different wireand the web is cured at 140° C. to crosslink binders around silica andfibers. The final product is the mat formed by the wetlaid process asdescribed above.

Example 2

About 1.0 g of glass fibers (for example Johns Manville Microstrand 100or 200 series) with diameter in the range from about 0.2 μm to about 0.8μm is combined together with about 0.1 g of synthetic polyester staplefiber and dispersed in water by using a blender. After blending for 30minutes, this mixture is dropped in a tank with a formation wire fixedat the bottom. The content is diluted further to get 0.01% of glassfiber in water. In a separate beaker, 10 g of precipitated silica isweighed and to this 4 gm of binder (for example Rhoplex HA-16) is added.The entire mixture is diluted with 200 ml of water. To this mixture,dilute sulfuric is added in drops until the clear liquid turns cloudyindicating coagulation or flocculation of binder around silica. Thismixture is dropped into the tank containing glass fiber and the wholemixture is stirred to make it homogeneous. The water is then drained byapplying suction from the bottom of the tank. The fibers, particles andbinders settle at the bottom on top of the formation wire, producing aweb that may contain around 30% of water. The water is further removedby vacuum suction. The web is then placed in an oven at 60° C. to drivethe remaining water off. The dried web is transferred to a differentwire and the web is cured at 140° C. to crosslink binders around silicaand fibers. The resulting product is the mat formed by wetlaid processas described above.

Example 3

About 2.0 g of glass fibers (for example Johns Manville Microstrand 100or 200 series) with diameter in the range from about 0.2 μm to about 0.8μm together with about 0.1 g of synthetic polyester staple fiber aredispersed in 1.0 L of water in a blender. After blending for 60 minutes,this is mixed with acid flocculated silica in binder from example #1.The entire mixture is diluted with 4 liters of water. This mixture isdropped over a moving Teflon formation wire carrier which is either flator inclined to drain water quickly by gravity and suction. The web onthe moving formation wire is passed through a furnace kept at 160° C.When the web moves through the furnace, the binder gets cured andcrosslinked. Curing results in binder crosslinking around silica andfiber network holding them all together intact. The mat thus formed willhave the enhanced strength to be used in lead acid batteries either asstand-alone separator or mat and/or as laminate or adjacent material orlayer with a polymer or polyethylene membrane, film, or separator. Forthe latter case, the fiber mat may be attached to a polyethyleneseparator by lamination or bonding, such as by epoxy lamination process,known in the industry.

Example 4

About 2.0 g of glass fibers (for example Johns Manville Microstrand 100or 200 series) with diameter in the range from about 0.2 μm to about 0.8μm together with about 0.1 g of synthetic polyester staple fiber aredispersed in 1.0 L of water in a blender. The fiber is diluted furtherto get 0.01% solution of fiber in water. This is formed on the movingformation wire and extra water is removed by suction. The water isremoved to an extent of less than 10% on the web. Using a rollerflocculated mixture of binder with silica is flooded onto the web. Theextra binder is sucked from the bottom of the web to be returned to thebinder/silica tank. Web with binder and silica mixture is fed throughthe furnace and the whole assembly is cured at about 140° C. to about160° C. for 5 minutes. The mat thus formed is fed between calenderingrolls and pressed together to the final thickness. The desired thicknessis in the range from about 0.45 mm to about 0.85 mm.

Example 5

About 2.0 g of glass fibers (for example Johns Manville Microstrand 100or 200 series) with diameter in the range from about 0.2 μm to about 0.8μm together with about 0.1 g of synthetic polyester staple fiber aredispersed in 1.0 L of water in a blender. The fiber is diluted furtherto get 0.01% solution of fiber in water. This is formed on the movingformation wire and extra water is removed by suction. The water isremoved to an extent of less than 5% on the web. The semi-dry web issprayed with a mixture of binder and silica in water. Suction is enabledto remove extra water, and the web is dried in oven and cured thereafterat 140° C. for 5 minutes. The mat is passed through the calenderingrollers at the end of the line to press the material to final form witha fixed thickness.

Example 6

About 1.0 g of glass fibers (for example Johns Manville Microstrand 100or 200 series) with diameter in the range from about 0.2 μm to about 0.8μm together with about 0.1 g of synthetic polyester staple fiber aredispersed in water by using a blender. Fiber web is formed on a movingformation wire and dried to less than 5% water. Flocculated silica inphenol-formaldehyde binder resin at a compositional weight ratio of 6:1is applied to this dry web, and excess binder is removed from thecarrier wire by suction. The web with silica and resin is cured infurnace at <200° C. for 5 minutes. The mat thus formed is rigid andchopped into cut pieces instead of in roll format.

Example 7

About 1.0 g of glass fibers (for example Johns Manville Microstrand 100or 200 series) with diameter in the range from about 0.2 μm to about 0.8μm together with about 0.1 g of synthetic polyester staple fiber aredispersed in water by using a blender. Fiber web is formed on a movingformation wire and dried to less than 5% water. Silica inphenol-formaldehyde binder resin at a compositional weight ratio of 6:1is applied to this dry web by using a roller loaded with the mixture.The excess binder is removed from the carrier wire by suction. The webwith silica and resin is cured in furnace at less than approximately200° C. for 5 minutes. The mat thus formed is rigid and chopped into cutpieces instead of in roll format.

Example 8

Flocculated silica similar to that described in the examples abovetogether with binder is applied by roller coat method on a wovenpolyester mesh with a starting basis weight of about 60 g/m². Theopenings in the mesh retain silica and binder. This loaded mesh ispressed between two rollers to a fixed thickness decided by the gapbetween the rollers. The mesh thus pressed will have a high density ofgreater than 130 g/m². This densified pressed mat is cured at 160° C. toform the final woven separator.

In certain Examples noted above, the binder used is Rhoplex HA-16,commercially available from Dow Chemicals. Its pH is around 2.6. Whensilica is mixed with this binder and acid is added, the pH will drop anddestabilize the emulsion resulting in flocculation. When flocculationhappens, binder traps silica with it forming huge particles orflocculates. The big particles have difficulty to pass through thenetwork and therefore get trapped easily in the network formingcomposite mat. If flocculation is not done, then individual silicaparticles may have easy access through fiber networks and may leave themat through the formation wire. Thus, in various embodiments that may bepreferred herein, in order to make a desirable composite mat, silicashould be a big particle or particles, and flocculation is preferred. Itis also possible to obtain silica particles as aggregates oragglomerates with the right or desired size that do not disperse intosmaller particles in water in a wet laid nonwoven process, such as theprocesses described herein. In such cases, flocculation may not berequired.

The silica-loaded nonwoven glass fiber separator mat disclosed hereinprovides many different advantages to lead acid batteries as has beenshown and described herein.

In accordance with at least selected embodiments, aspects or objects,the present disclosure or invention is directed to novel or improvedmats, fibrous layers, separators, fibrous separators, compositeseparators, composite mat separators, composite mat separatorscontaining fibers and silica particles, battery separators, lead acidbattery separators, plate wraps, and/or pasting papers, and/orbatteries, cells, plates, and/or methods of manufacture and/or use ofsuch mats, layers, separators, battery separators, lead acid batteryseparators, papers, wraps, batteries, plates, plate systems, wrappedplates, pocketed plates, and/or cells, as well as vehicles, systems, ordevices containing the same. In accordance with at least certainembodiments, the present disclosure or invention is directed to novel orimproved enhanced composite separators for lead acid batteries, and/orimproved methods of making and/or using such improved separators, cells,batteries, systems, vehicles, and/or the like. In accordance with atleast certain embodiments, the present disclosure or invention isdirected to an improved composite separator for lead acid batteriesand/or improved methods of using such batteries having such improvedseparators. In accordance with at least selected embodiments, thepresent disclosure or invention is directed to composite separators,particularly separators for lead acid batteries, flooded batteries,enhanced flooded batteries, dry charge batteries, and/or the like. Inaddition, disclosed herein are methods, systems and battery separatorsfor enhancing battery life, decreasing shorting, reducing water loss,increasing wettability, reducing acid stratification, improving aciddiffusion, reducing active material shedding, reducing metal inducedoxidation, reducing oxidation, reducing heavy metal and/or metalloidpoisoning, reducing antimony poisoning, increasing antimony suppression,and/or improving uniformity in one or more lead acid batteries. Inaccordance with at least particular embodiments, the present disclosureor invention is directed to an improved separator for lead acidbatteries wherein the separator includes fibers, one or more binders,silica particles, fillers, additives, surfactants, coatings and/or thelike.

Disclosed herein are novel or improved mats, fibrous layers, composites,composite separators, separators, battery separators, lead acid batteryseparators, wraps, sleeves, envelopes, pockets, pasting papers, and/orflooded lead acid battery separators, and/or batteries, cells, and/ormethods of manufacture and/or use of such mats, fibrous layers,composites, composite separators, separators, battery separators, leadacid battery separators, wraps, papers, cells, plates, wrapped plates,plate systems, pocketed plates, and/or batteries. In addition, disclosedherein are methods, systems, and battery separators for enhancingbattery life, reducing internal resistance, reducing metalloidpoisoning, reducing acid stratification, and/or improving uniformity inat least enhanced flooded batteries. In accordance with at leastparticular embodiments, the present disclosure or invention is directedto an improved separator for lead acid batteries wherein the separatoris a composite mat containing fibers and silica particles.

Also disclosed or contemplated are novel or improved lead acid batteryseparator containing at least one separator layer or material comprisinga composite or composite layer of fibers and particles, of fibers andbinder including particles, of fibers and agglomerated particles, offibers and flocculated particles, of fibers and binder flocculatedparticles, of particle-binder mixture impregnated on nonwoven or wovenglass or synthetic mat, of particle impregnated on a mesh or net, offibers, a mesh and particles, or of agglomerated flocculated particlesand fibers or a mesh.

The compositions and methods of the appended claims are not limited inscope by the specific compositions and methods described herein, whichare intended as illustrations of a few aspects of the claims and anycompositions and methods that are functionally equivalent are intendedto fall within the scope of the claims. Various modifications of thecompositions and methods in addition to those shown and described hereinare intended to fall within the scope of the appended claims. Further,while only certain representative compositions and method stepsdisclosed herein are specifically described, other combinations of thecompositions and method steps also are intended to fall within the scopeof the appended claims, even if not specifically recited. Thus, acombination of steps, elements, components, or constituents may beexplicitly mentioned herein or less, however, other combinations ofsteps, elements, components, and constituents are included, even thoughnot explicitly stated. The term “comprising” and variations thereof asused herein is used synonymously with the term “including” andvariations thereof and are open, non-limiting terms. Although the terms“comprising” and “including” have been used herein to describe variousembodiments, the terms “consisting essentially of” and “consisting of”may be used in place of “comprising” and “including” to provide for morespecific embodiments of the invention and are also disclosed. Other thanin the examples, or where otherwise noted, all numbers expressingquantities of ingredients, reaction conditions, and so forth used in thespecification and claims are to be understood at the very least, and notas an attempt to limit the application of the doctrine of equivalents tothe scope of the claims, to be construed in light of the number ofsignificant digits and ordinary rounding approaches.

The present invention may be embodied in other forms without departingfrom the spirit and the essential attributes thereof, and, accordingly,reference should be made to the appended claims, rather than to theforegoing specification, as indicating the scope of the invention.Disclosed are components that may be used to perform the disclosedmethods and systems. These and other components are disclosed herein,and it is understood that when combinations, subsets, interactions,groups, etc. of these components are disclosed that while specificreference of each various individual and collective combinations andpermutation of these may not be explicitly disclosed, each isspecifically contemplated and described herein, for all methods andsystems. This applies to all aspects of this application including, butnot limited to, steps in disclosed methods. Thus, if there are a varietyof additional steps that may be performed it is understood that each ofthese additional steps may be performed with any specific embodiment orcombination of embodiments of the disclosed methods.

The foregoing written description of structures and methods has beenpresented for purposes of illustration only. Examples are used todisclose exemplary embodiments, including the best mode, and also toenable any person skilled in the art to practice the invention,including making and using any devices or systems and performing anyincorporated methods. These examples are not intended to be exhaustiveor to limit the invention to the precise steps and/or forms disclosed,and many modifications and variations are possible in light of the aboveteaching. Features described herein may be combined in any combination.Steps of a method described herein may be performed in any sequence thatis physically possible. The patentable scope of the invention is definedby the appended claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral language of the claims.

The compositions and methods of the appended claims are not limited inscope by the specific compositions and methods described herein, whichare intended as illustrations of a few aspects of the claims. Anycompositions and methods that are functionally equivalent are intendedto fall within the scope of the claims. Various modifications of thecompositions and methods in addition to those shown and described hereinare intended to fall within the scope of the appended claims. Further,while only certain representative compositions and method stepsdisclosed herein are specifically described, other combinations of thecompositions and method steps also are intended to fall within the scopeof the appended claims, even if not specifically recited. Thus, acombination of steps, elements, components, or constituents may beexplicitly mentioned herein or less, however, other combinations ofsteps, elements, components, and constituents are included, even thoughnot explicitly stated.

As used in the specification and the appended claims, the singular forms“a,” “an,” and “the” include plural referents unless the context clearlydictates otherwise. Ranges may be expressed herein as from “about” or“approximately” one particular value, and/or to “about” or“approximately” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. Itwill be further understood that the endpoints of each of the ranges aresignificant both in relation to the other endpoint, and independently ofthe other endpoint. “Optional” or “optionally” means that thesubsequently described event or circumstance may or may not occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

Throughout the description and claims of this specification, the word“comprise” and variations of the word, such as “comprising” and“comprises,” means “including but not limited to,” and is not intendedto exclude, for example, other additives, components, integers, orsteps. The terms “consisting essentially of” and “consisting of” may beused in place of “comprising” and “including” to provide for morespecific embodiments of the invention and are also disclosed.“Exemplary” or “for example” means “an example of” and is not intendedto convey an indication of a preferred or ideal embodiment. Similarly,“such as” is not used in a restrictive sense, but for explanatory orexemplary purposes.

Other than where noted, all numbers expressing geometries, dimensions,and so forth used in the specification and claims are to be understoodat the very least, and not as an attempt to limit the application of thedoctrine of equivalents to the scope of the claims, to be construed inlight of the number of significant digits and ordinary roundingapproaches.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of skill in the artto which the disclosed invention belongs. Publications cited herein andthe materials for which they are cited are specifically incorporated byreference.

The present invention may be embodied in other forms without departingfrom the spirit and the essential attributes thereof, and, accordingly,reference should be made to the appended claims, rather than to theforegoing specification, as indicating the scope of the invention.

Additionally, the invention illustratively disclosed herein suitably maybe practiced in the absence of any element which is not specificallydisclosed herein.

1.-35. (canceled)
 36. A battery separator comprising embossed ribs orother embossments, and wherein the battery separator comprises fibers.37. The battery separator of claim 36, wherein the battery separatorcomprises embossed ribs.
 38. The battery separator of claim 36, whereinthe fibers comprise glass fibers, synthetic fibers, ceramic fibers, orcombinations thereof.
 39. The battery separator of claim 38, wherein thefibers comprise glass fibers.
 40. The battery separator of claim 38,wherein the fibers comprise glass fibers and synthetic fibers.
 41. Thebattery separator of claim 36, comprising fibers, silica, and binder.42. The battery separator of claim 41, wherein the fibers comprise glassfibers, synthetic fibers, ceramic fibers, or combinations thereof. 43.The battery separator of claim 42, wherein the fibers comprise glassfibers and synthetic fibers.
 44. The battery separator of claim 41,wherein the silica is flocculated silica.
 45. The battery separator ofclaim 41, wherein the binder is a resin binder or a polymeric binder.46. An AGM Battery comprising the battery separator of claim
 36. 47. AnAGM Battery comprising the battery separator of claim
 39. 48. An AGMBattery comprising the battery separator of claim
 40. 49. A VRLA-AGMbattery comprising the battery separator of claim
 36. 50. A VRLA-AGMbattery comprising the battery separator of claim
 39. 51. A VRLA-AGMbattery comprising the battery separator of claim
 40. 52. A floodedbattery comprising the battery separator of claim
 36. 53. An enhancedflooded battery comprising the battery separator of claim
 36. 54. Abattery comprising the battery separator of claim 36, wherein thebattery separator does one or more of the following: enhance batterylife, reduce internal resistance, reduce metalloid poisoning, reduceacid stratification, and improve uniformity.
 55. The battery of claim54, wherein the battery separator reduces acid stratification.